Forebodings of an Old Man

Sacrifice a creature. Put a creature from your graveyard on the top of your library.
"When the full moon shines o'er the temple deep,
A sacrifice will stir from sleep
The legions of a long forgotten lord.
When a fair royal maid on the altar dies,
The dead of Maakengorge shall rise
To claim their long-awaited reward." - Old Man